From: Jan Kiszka <jan.kiszka@web.de>
To: Avi Kivity <avi@redhat.com>, Marcelo Tosatti <mtosatti@redhat.com>
Cc: kvm <kvm@vger.kernel.org>, "Roedel, Joerg" <Joerg.Roedel@amd.com>
Subject: [PATCH v2] KVM: x86: Fix guest debug across vcpu INIT reset
Date: Fri, 21 Sep 2012 05:42:55 +0200 [thread overview]
Message-ID: <505BE23F.5090200@web.de> (raw)
In-Reply-To: <505B006A.2030604@redhat.com>
From: Jan Kiszka <jan.kiszka@siemens.com>
If we reset a vcpu on INIT, we so far overwrote dr7 as provided by
KVM_SET_GUEST_DEBUG, and we also cleared switch_db_regs unconditionally.
Fix this by saving the dr7 used for guest debugging and calculating the
effective register value as well as switch_db_regs on any potential
change. This will change to focus of the set_guest_debug vendor op to
update_dp_bp_intercept.
Found while trying to stop on start_secondary.
Signed-off-by: Jan Kiszka <jan.kiszka@siemens.com>
---
arch/x86/include/asm/kvm_host.h | 4 ++--
arch/x86/kvm/svm.c | 23 ++++-------------------
arch/x86/kvm/vmx.c | 14 +-------------
arch/x86/kvm/x86.c | 26 +++++++++++++++++---------
4 files changed, 24 insertions(+), 43 deletions(-)
diff --git a/arch/x86/include/asm/kvm_host.h b/arch/x86/include/asm/kvm_host.h
index 64adb61..e8baa1c 100644
--- a/arch/x86/include/asm/kvm_host.h
+++ b/arch/x86/include/asm/kvm_host.h
@@ -457,6 +457,7 @@ struct kvm_vcpu_arch {
unsigned long dr6;
unsigned long dr7;
unsigned long eff_db[KVM_NR_DB_REGS];
+ unsigned long guest_debug_dr7;
u64 mcg_cap;
u64 mcg_status;
@@ -621,8 +622,7 @@ struct kvm_x86_ops {
void (*vcpu_load)(struct kvm_vcpu *vcpu, int cpu);
void (*vcpu_put)(struct kvm_vcpu *vcpu);
- void (*set_guest_debug)(struct kvm_vcpu *vcpu,
- struct kvm_guest_debug *dbg);
+ void (*update_db_bp_intercept)(struct kvm_vcpu *vcpu);
int (*get_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 *pdata);
int (*set_msr)(struct kvm_vcpu *vcpu, u32 msr_index, u64 data);
u64 (*get_segment_base)(struct kvm_vcpu *vcpu, int seg);
diff --git a/arch/x86/kvm/svm.c b/arch/x86/kvm/svm.c
index 611c728..076064b 100644
--- a/arch/x86/kvm/svm.c
+++ b/arch/x86/kvm/svm.c
@@ -1146,7 +1146,6 @@ static void init_vmcb(struct vcpu_svm *svm)
svm_set_efer(&svm->vcpu, 0);
save->dr6 = 0xffff0ff0;
- save->dr7 = 0x400;
kvm_set_rflags(&svm->vcpu, 2);
save->rip = 0x0000fff0;
svm->vcpu.arch.regs[VCPU_REGS_RIP] = save->rip;
@@ -1643,7 +1642,7 @@ static void svm_set_segment(struct kvm_vcpu *vcpu,
mark_dirty(svm->vmcb, VMCB_SEG);
}
-static void update_db_intercept(struct kvm_vcpu *vcpu)
+static void update_db_bp_intercept(struct kvm_vcpu *vcpu)
{
struct vcpu_svm *svm = to_svm(vcpu);
@@ -1663,20 +1662,6 @@ static void update_db_intercept(struct kvm_vcpu *vcpu)
vcpu->guest_debug = 0;
}
-static void svm_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
-{
- struct vcpu_svm *svm = to_svm(vcpu);
-
- if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
- svm->vmcb->save.dr7 = dbg->arch.debugreg[7];
- else
- svm->vmcb->save.dr7 = vcpu->arch.dr7;
-
- mark_dirty(svm->vmcb, VMCB_DR);
-
- update_db_intercept(vcpu);
-}
-
static void new_asid(struct vcpu_svm *svm, struct svm_cpu_data *sd)
{
if (sd->next_asid > sd->max_asid) {
@@ -1748,7 +1733,7 @@ static int db_interception(struct vcpu_svm *svm)
if (!(svm->vcpu.guest_debug & KVM_GUESTDBG_SINGLESTEP))
svm->vmcb->save.rflags &=
~(X86_EFLAGS_TF | X86_EFLAGS_RF);
- update_db_intercept(&svm->vcpu);
+ update_db_bp_intercept(&svm->vcpu);
}
if (svm->vcpu.guest_debug &
@@ -3659,7 +3644,7 @@ static void enable_nmi_window(struct kvm_vcpu *vcpu)
*/
svm->nmi_singlestep = true;
svm->vmcb->save.rflags |= (X86_EFLAGS_TF | X86_EFLAGS_RF);
- update_db_intercept(vcpu);
+ update_db_bp_intercept(vcpu);
}
static int svm_set_tss_addr(struct kvm *kvm, unsigned int addr)
@@ -4259,7 +4244,7 @@ static struct kvm_x86_ops svm_x86_ops = {
.vcpu_load = svm_vcpu_load,
.vcpu_put = svm_vcpu_put,
- .set_guest_debug = svm_guest_debug,
+ .update_db_bp_intercept = update_db_bp_intercept,
.get_msr = svm_get_msr,
.set_msr = svm_set_msr,
.get_segment_base = svm_get_segment_base,
diff --git a/arch/x86/kvm/vmx.c b/arch/x86/kvm/vmx.c
index d62b413..b0f7b34 100644
--- a/arch/x86/kvm/vmx.c
+++ b/arch/x86/kvm/vmx.c
@@ -2286,16 +2286,6 @@ static void vmx_cache_reg(struct kvm_vcpu *vcpu, enum kvm_reg reg)
}
}
-static void set_guest_debug(struct kvm_vcpu *vcpu, struct kvm_guest_debug *dbg)
-{
- if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
- vmcs_writel(GUEST_DR7, dbg->arch.debugreg[7]);
- else
- vmcs_writel(GUEST_DR7, vcpu->arch.dr7);
-
- update_exception_bitmap(vcpu);
-}
-
static __init int cpu_has_kvm_support(void)
{
return cpu_has_vmx();
@@ -3959,8 +3949,6 @@ static int vmx_vcpu_reset(struct kvm_vcpu *vcpu)
kvm_rip_write(vcpu, 0);
kvm_register_write(vcpu, VCPU_REGS_RSP, 0);
- vmcs_writel(GUEST_DR7, 0x400);
-
vmcs_writel(GUEST_GDTR_BASE, 0);
vmcs_write32(GUEST_GDTR_LIMIT, 0xffff);
@@ -7241,7 +7229,7 @@ static struct kvm_x86_ops vmx_x86_ops = {
.vcpu_load = vmx_vcpu_load,
.vcpu_put = vmx_vcpu_put,
- .set_guest_debug = set_guest_debug,
+ .update_db_bp_intercept = update_exception_bitmap,
.get_msr = vmx_get_msr,
.set_msr = vmx_set_msr,
.get_segment_base = vmx_get_segment_base,
diff --git a/arch/x86/kvm/x86.c b/arch/x86/kvm/x86.c
index c4d451e..355d7a8 100644
--- a/arch/x86/kvm/x86.c
+++ b/arch/x86/kvm/x86.c
@@ -692,6 +692,18 @@ unsigned long kvm_get_cr8(struct kvm_vcpu *vcpu)
}
EXPORT_SYMBOL_GPL(kvm_get_cr8);
+static void kvm_update_dr7(struct kvm_vcpu *vcpu)
+{
+ unsigned long dr7;
+
+ if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)
+ dr7 = vcpu->arch.guest_debug_dr7;
+ else
+ dr7 = vcpu->arch.dr7;
+ kvm_x86_ops->set_dr7(vcpu, dr7);
+ vcpu->arch.switch_db_regs = (dr7 & DR7_BP_EN_MASK);
+}
+
static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
{
switch (dr) {
@@ -717,10 +729,7 @@ static int __kvm_set_dr(struct kvm_vcpu *vcpu, int dr, unsigned long val)
if (val & 0xffffffff00000000ULL)
return -1; /* #GP */
vcpu->arch.dr7 = (val & DR7_VOLATILE) | DR7_FIXED_1;
- if (!(vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP)) {
- kvm_x86_ops->set_dr7(vcpu, vcpu->arch.dr7);
- vcpu->arch.switch_db_regs = (val & DR7_BP_EN_MASK);
- }
+ kvm_update_dr7(vcpu);
break;
}
@@ -5853,13 +5862,12 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
if (vcpu->guest_debug & KVM_GUESTDBG_USE_HW_BP) {
for (i = 0; i < KVM_NR_DB_REGS; ++i)
vcpu->arch.eff_db[i] = dbg->arch.debugreg[i];
- vcpu->arch.switch_db_regs =
- (dbg->arch.debugreg[7] & DR7_BP_EN_MASK);
+ vcpu->arch.guest_debug_dr7 = dbg->arch.debugreg[7];
} else {
for (i = 0; i < KVM_NR_DB_REGS; i++)
vcpu->arch.eff_db[i] = vcpu->arch.db[i];
- vcpu->arch.switch_db_regs = (vcpu->arch.dr7 & DR7_BP_EN_MASK);
}
+ kvm_update_dr7(vcpu);
if (vcpu->guest_debug & KVM_GUESTDBG_SINGLESTEP)
vcpu->arch.singlestep_rip = kvm_rip_read(vcpu) +
@@ -5871,7 +5879,7 @@ int kvm_arch_vcpu_ioctl_set_guest_debug(struct kvm_vcpu *vcpu,
*/
kvm_set_rflags(vcpu, rflags);
- kvm_x86_ops->set_guest_debug(vcpu, dbg);
+ kvm_x86_ops->update_db_bp_intercept(vcpu);
r = 0;
@@ -6043,10 +6051,10 @@ int kvm_arch_vcpu_reset(struct kvm_vcpu *vcpu)
vcpu->arch.nmi_pending = 0;
vcpu->arch.nmi_injected = false;
- vcpu->arch.switch_db_regs = 0;
memset(vcpu->arch.db, 0, sizeof(vcpu->arch.db));
vcpu->arch.dr6 = DR6_FIXED_1;
vcpu->arch.dr7 = DR7_FIXED_1;
+ kvm_update_dr7(vcpu);
kvm_make_request(KVM_REQ_EVENT, vcpu);
vcpu->arch.apf.msr_val = 0;
--
1.7.3.4
next prev parent reply other threads:[~2012-09-21 3:43 UTC|newest]
Thread overview: 4+ messages / expand[flat|nested] mbox.gz Atom feed top
2012-09-19 19:38 [PATCH] KVM: x86: Fix guest debug across vcpu INIT reset Jan Kiszka
2012-09-20 11:39 ` Avi Kivity
2012-09-21 3:42 ` Jan Kiszka [this message]
2012-09-23 13:01 ` [PATCH v2] " Avi Kivity
Reply instructions:
You may reply publicly to this message via plain-text email
using any one of the following methods:
* Save the following mbox file, import it into your mail client,
and reply-to-all from there: mbox
Avoid top-posting and favor interleaved quoting:
https://en.wikipedia.org/wiki/Posting_style#Interleaved_style
* Reply using the --to, --cc, and --in-reply-to
switches of git-send-email(1):
git send-email \
--in-reply-to=505BE23F.5090200@web.de \
--to=jan.kiszka@web.de \
--cc=Joerg.Roedel@amd.com \
--cc=avi@redhat.com \
--cc=kvm@vger.kernel.org \
--cc=mtosatti@redhat.com \
/path/to/YOUR_REPLY
https://kernel.org/pub/software/scm/git/docs/git-send-email.html
* If your mail client supports setting the In-Reply-To header
via mailto: links, try the mailto: link
Be sure your reply has a Subject: header at the top and a blank line
before the message body.
This is an external index of several public inboxes,
see mirroring instructions on how to clone and mirror
all data and code used by this external index.